Conventional coasters such as skateboards and scooters generally consist of a foot board or platform for one or both feet of the rider and front and rear wheels supporting the platform on the ground for rolling movement. In skateboards, the front and rear wheels typically are fixed against turning to the underside of the platform, and steering of the skateboard is effected by means other than turning the front or rear wheels. On the other hand, scooters typically employ steering handles which turn or steer the front wheel mounted thereon, such handle and wheel assembly being pivoted to the foot platform. For an example of a scooter employing a steerable front wheel, reference may be had to U.S. Pat. No. 2,460,395.
Other coasters are known and disclosed in the patented prior art. The toy coaster described in U.S. Pat. No. 3,771,811 includes a circular rear steering platform pivoted on a rigid elongated foot platform. The front wheels of the coaster are secured to the underside of the foot platform at its front end, whereas the rear wheels are secured to the underside of the rear steering platform. Steering action is acieved by turning of the foot resting on the rear steering platform.
The scooter described in U.S. Pat. No. 4,093,252 includes a board balancing and maneuvering handle fixed to the forward end of the foot board. In contrast to the typical scooter, the foot board has secured therebeneath, fore and aft, caster wheels which freely swivel through 360.degree.. Turning of such scooter is achieved primarily by the rider shifting his/her weight and applying pressure with his/her feet to the foot board in a variety of modes.
Although not particularly relevant to the coaster art, U.S. Pat. No. 102,423 discloses a velocipede including two non-steerable but driveable rear wheels and a single front steering wheel. The steering wheel is supported on an axle having slotted bearings at its opposite axial ends. The slotted bearings slide on respective curved segments secured to the velocipede frame. Connecting rods are connected between the slotted bearings and the ends of a cross-bar pivoted on the velocipede frame and manipulable by the rider to effect front wheel steerage.